This present invention relates to an electrodynamically opening contact system having fixed and a movable contact element. More specifically, the invention comprehends a contact set including a spring means which biases the contacts in both an open and a closed position.
An electrodynamically opening contact system according to the prior art, such as that disclosed in German Pat. No. 1,079,176 incorporates a spring arrangement with two parallel mounted, prestressed tension springs. The springs are both mounted on one end, and at the other end hooked around a pin which traverses a rotating contact element. In the closed contact position the two tension springs generate a contact force on the rotating contact element. As soon as excess current flows through the closed contacts, the rotating contact is thrown away from the fixed contact element by means of an electrodynamic force which acts against the contact force produced by the spring arrangment. At a preset opening angle between the fixed and the rotating contact element the direction of the torque exerted by the spring arrangment on the rotating contact reverses, so that the further opening of the contact is accelerated by the spring arrangement.
It is accordingly an object of this invention to provide an improved electrodynamically opening contact system which in its closed position demonstrates a relatively high contact force but opens with great rapidity and reliability when excess current arises.